1
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Nguyen Quoc B, Cavanaugh SK, Hunt KA, Bryson SJ, Winkler MKH. Impact of aerobic granular sludge sizes and dissolved oxygen concentration on greenhouse gas N 2O emission. WATER RESEARCH 2024; 255:121479. [PMID: 38520777 DOI: 10.1016/j.watres.2024.121479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 03/13/2024] [Accepted: 03/14/2024] [Indexed: 03/25/2024]
Abstract
Aerobic granular sludge (AGS) at wastewater treatment plants (WWTPs) are known to produce nitrous oxide (N2O), a greenhouse gas which has a ∼300 times higher global warming potential than carbon dioxide. In this research, we studied N2O emissions from different sizes of AGS developed at a dissolved oxygen (DO) level of 2 mgO2/L while exposing them to disturbances at various DO concentrations ranging from 1 to 4 mgO2/L. Five different AGS size classes were studied: 212-600 µm, 600-1000 µm, 1000-1400 µm, 1400-2000 µm, and > 2000 µm. Metagenomic data showed N2O reductase genes (nosZ) were more abundant in the smaller AGS sizes which aligned with the observation of higher N2O reduction rates in small AGS under anaerobic conditions. However, when oxygen was present, the activity measurements of N2O emission showed an opposite trend compared to metagenomic data, smaller AGS (212 to 1000 µm) emitted significantly higher N2O (p < 0.05) than larger AGS (1000 µm to >2000 µm) at DO of 2, 3, and 4 mgO2/L. The N2O emission rate showed positive correlation with both oxygen levels and nitrification rate. This pattern indicates a connection between N2O emission and nitrification. In addition, the data suggested the penetration of oxygen into the anoxic zone of granules might have hindered nitrous oxide reduction, resulting in incomplete denitrification stopping at N2O and consequently contributing to an increase in N2O emissions. This work sets the stage to better understand the impacts of AGS size on N2O emissions in WWTPs under different disturbance of DO conditions, and thus ensure that wastewater treatment will comply with possible future regulations demanding lowering greenhouse gas emissions in an effort to combat climate change.
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Affiliation(s)
- Bao Nguyen Quoc
- Department of Civil and Environmental Engineering, University of Washington, United States.
| | - Shannon K Cavanaugh
- Department of Civil and Environmental Engineering, University of Washington, United States
| | - Kristopher A Hunt
- Department of Civil and Environmental Engineering, University of Washington, United States
| | - Samuel J Bryson
- Department of Civil and Environmental Engineering, University of Washington, United States
| | - Mari K H Winkler
- Department of Civil and Environmental Engineering, University of Washington, United States
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2
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Walter XA, Kostrytsia A, Watson H, Winfield J, Baran A, Gillman S. Novel self-stratifying bioelectrochemical system for municipal wastewater treatment halves nitrous oxide emissions. BIORESOURCE TECHNOLOGY 2024; 392:129969. [PMID: 37979344 DOI: 10.1016/j.biortech.2023.129969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 10/27/2023] [Accepted: 10/31/2023] [Indexed: 11/20/2023]
Abstract
Reducing carbon footprint and greenhouse gas emissions are prime global goals. Wastewater treatment contributes significantly, and this study developed a technology with a focus on utilisation in small-decentralised plants. Bioelectrochemical systems (BES) utilise bacteria to remove pollutants while generating power and a range of experiments were performed to investigate their suitability compared to conventional trickling filters. A lab-based trickling filter was inferior to one adapted with electrodes both in terms of organic matter (COD) and phosphate reduction, but the BES did not generate electrical output due to inferior cathode configuration. An enhanced, novel, dual-BES system was developed with improved cathode positioning and operated as a cascade. This demonstrated improved COD (79 %) and total nitrogen (102 %) removal over the trickling filter. Concomitantly it emitted 47 % less N2O and generated an electrical output of 0.62 mA at 311 mV. Further work is needed to optimise BES but these results are encouraging in the development of sustainable biotechnologies.
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Affiliation(s)
- Xavier Alexis Walter
- Environmental and Biochemical Science Department, James Hutton Institute, Craigiebuckler, Aberdeen AB15 8QH, UK.
| | | | - Helen Watson
- Environmental and Biochemical Science Department, James Hutton Institute, Craigiebuckler, Aberdeen AB15 8QH, UK
| | - Jonathan Winfield
- Faculty of Environment and Technology, Frenchay Campus, University of the West of England, Bristol BS16 1QY, UK
| | - Anna Baran
- Research and Innovation Department, Scottish Water, 6 Buchanan Gate, Cumbernauld Road, Stepps G33 6FB, UK
| | - Sarah Gillman
- Research and Innovation Department, Scottish Water, 6 Buchanan Gate, Cumbernauld Road, Stepps G33 6FB, UK
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3
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Qin J, Ying J, Li H, Qiu R, Lin C. Rainwater input reduces greenhouse gas emission and arsenic uptake in paddy rice systems. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 902:166096. [PMID: 37558067 DOI: 10.1016/j.scitotenv.2023.166096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 07/23/2023] [Accepted: 08/05/2023] [Indexed: 08/11/2023]
Abstract
This work aimed to test the hypothesis that rainwater-borne hydrogen peroxide (H2O2) can affect arsenic uptake by rice plants and emission of greenhouse gases in paddy rice systems. A mesocosm rice plant growth experiment, in conjunction with rainwater monitoring, was conducted to examine the effects of rainwater input on functional groups of soil microorganisms related to transformation of arsenic, carbon and nitrogen as well as various arsenic species in the soil and plant systems. The fluxes of methane (CH4), nitrous oxide (N2O) and carbon dioxide (CO2) were measured during selected rainfall events. The results showed that rainwater-borne H2O2 effectively reacted with Fe2+ present in paddy soil to trigger a Fenton-like reaction to produce •OH. Both H2O2 and •OH inhibited As(V)-reducing microbes but promoted As(III)-oxidizing microbes, leading to a net increase in arsenate-As that is less phytoavailable compared to arsenite-As. This impeded uptake of soil-borne As by the rice plant roots, and consequently reduced the accumulation of As in the rice grains. The input of H2O2 into the soil caused more inhibition to methanogens than to methane-oxidizing microbes, resulting in a reduction in CH4 flux. The microbes mediating the transformation of inorganic nitrogen were also under oxidative stresses upon exposure to the rainwater-derived H2O2. And the limited conversion of NO3- to NO played a crucial role in reducing N2O emission from the paddy soils. The results also indicated that the rainwater-borne H2O2 could significantly affect other biogeochemical processes that shape the wider ecosystems, which is worth further investigations.
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Affiliation(s)
- Junhao Qin
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
| | - Jidong Ying
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
| | - Huashou Li
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
| | - Rongliang Qiu
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
| | - Chuxia Lin
- Centre for Regional and Rural Futures, Faculty of Science, Engineering and Built Environment, Deakin University, Burwood, VIC 3125, Australia.
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Shao L, Wang D, Chen G, Zhao X, Fan L. Advance in the sulfur-based electron donor autotrophic denitrification for nitrate nitrogen removal from wastewater. World J Microbiol Biotechnol 2023; 40:7. [PMID: 37938419 DOI: 10.1007/s11274-023-03802-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Accepted: 10/09/2023] [Indexed: 11/09/2023]
Abstract
In the field of wastewater treatment, nitrate nitrogen (NO3--N) is one of the significant contaminants of concern. Sulfur autotrophic denitrification technology, which uses a variety of sulfur-based electron donors to reduce NO3--N to nitrogen (N2) through sulfur autotrophic denitrification bacteria, has emerged as a novel nitrogen removal technology to replace heterotrophic denitrification in the field of wastewater treatment due to its low cost, environmental friendliness, and high nitrogen removal efficiency. This paper reviews the advance of reduced sulfur compounds (such as elemental sulfur, sulfide, and thiosulfate) and iron sulfides (such as ferrous sulfide, pyrrhotite, and pyrite) electron donors for treating NO3--N in wastewater by sulfur autotrophic denitrification technology, including the dominant bacteria types and the sulfur autotrophic denitrification process based on various electron donors are introduced in detail, and their operating costs, nitrogen removal performance and impacts on the ecological environment are analyzed and compared. Moreover, the engineering applications of sulfur-based electron donor autotrophic denitrification technology were comprehensively summarized. According to the literature review, the focus of future industry research were discussed from several aspects as well, which would provide ideas for the application and optimization of the sulfur autotrophic denitrification process for deep and efficient removal of NO3--N in wastewater.
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Affiliation(s)
- Lixin Shao
- School of Mechanical Engineering, Shenyang University of Technology, Shenyang, 110870, China
| | - Dexi Wang
- School of Mechanical Engineering, Shenyang University of Technology, Shenyang, 110870, China
| | - Gong Chen
- School of Chemical Equipment, Shenyang University of Technology, Liaoyang, 111000, China
| | - Xibo Zhao
- Weihai Baike Environmental Protection Engineering Co., Ltd., Weihai, 264200, China
| | - Lihua Fan
- School of Chemical Equipment, Shenyang University of Technology, Liaoyang, 111000, China.
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5
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Read-Daily B, Ben Maamar S, Sabba F, Green S, Nerenberg R. Effect of nitrous oxide (N 2O) on the structure and function of nitrogen-oxide reducing microbial communities. CHEMOSPHERE 2022; 307:135819. [PMID: 35977570 DOI: 10.1016/j.chemosphere.2022.135819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 07/18/2022] [Accepted: 07/20/2022] [Indexed: 06/15/2023]
Abstract
Nitrous oxide (N2O) is a potent greenhouse gas that can be produced by nitrifying and denitrifying bacteria. Yet the effects of N2O on microbial communities is not well understood. We used batch tests to explore the effects of N2O on mixed denitrifying communities. Batch tests were carried out with acetate as the electron donor and with the following electron acceptors: nitrate (NO3-), nitrite (NO2-), N2O, NO3- + N2O, and NO2- + N2O. Activated sludge from a municipal wastewater treatment plant was used as the inoculum. The bacteria grew readily with N2O as the sole acceptor. When N2O was provided along with NO3- or NO2-, it was used concurrently and resulted in higher growth rates than the same acceptors without added N2O. The microbial communities resulting from N2O addition were significantly different at the genus level from those with just NO3- or NO2-. Tests with N2O as the sole added acceptor revealed a reduced diversity. Analysis of inferred gene content using PICRUSt2 indicated a greater abundance of genera with a complete denitrification pathway when growing on N2O or NO2-, relative to all other tests. This suggests that specific N2O reduction rates are high, and that N2O alone selects for a low-diversity, fully denitrifying community. When N2O is present with NO2- or NO3-, the microbial communities were more diverse and did not select exclusively for full denitrifiers. N2O alone appears to select for a "generalist" community with full denitrification pathways and lower diversity. In terms of denitrification genes, the combination of acceptors with N2O appeared to increase the number of microbes carrying nirK, while fully denitrifying bacteria appear more likely to carry nirS. Lastly, all the taxa in NO2- and N2O samples were predicted to harbor nosZ. This suggests the potential for reduced N2O emissions in denitrifying systems.
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Affiliation(s)
- B Read-Daily
- Department of Engineering and Physics, Elizabethtown College, Elizabethtown, PA, 17022, USA; Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - S Ben Maamar
- Samuel J. Wood Library, Weill Cornell Medicine, New York, NY, 10065, USA
| | - F Sabba
- Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, IN, 46556, USA; Black & Veatch, KS, USA
| | - S Green
- Rush Medical College, Chicago, IL, 60612, USA
| | - R Nerenberg
- Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, IN, 46556, USA.
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6
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Sabba F, McNamara P, Redmond E, Ruff C, Young M, Downing L. Lab-scale data and microbial community structure suggest shortcut nitrogen removal as the predominant nitrogen removal mechanism in post-aerobic digestion (PAD). WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2022; 94:e10762. [PMID: 35809034 DOI: 10.1002/wer.10762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Revised: 06/11/2022] [Accepted: 06/20/2022] [Indexed: 06/15/2023]
Abstract
Implementing an aerobic digestion step after anaerobic digestion, referred to as "post aerobic digestion" (PAD), can remove ammonia without the need for an external carbon source and destroy volatile solids. While this process has been documented at the lab-scale and full-scale, the mechanism for N removal and the corresponding microbial community that carries out this process have not been established. This research gap is important to fill because the nitrogen removal pathway has implications on aeration requirements and carbon demand, that is, short-cut N-removal requires less oxygen and carbon than simultaneous nitrification-denitrification. The aims of this research were to (i) determine if nitrite (NO2 - ) or nitrate (NO3 - ) dominates following ammonia removal and (ii) characterize the microbial community from PAD reactors. Here, lab-scale PAD reactors were seeded with biomass from two different full-scale PAD reactors. The lab-scale reactors were fed with biomass from full-scale reactors and operated in batch mode to quantify nitrogen species concentrations (ammonia, NH4 + , NO2 - , and NO3 - ) over time. Experimental results revealed that NO2 - production rates were several orders of magnitude greater than NO3 - production rates. Indeed, nitrite accumulation rate (NAR) was greater than 90% at most temperatures, confirming that shortcut nitrogen removal was the dominant NH4 + removal mechanism in PAD. Microbial community analysis via 16S rRNA sequencing indicated that ammonia oxidizing bacteria (AOB) were much more abundant than nitrite oxidizing bacteria (NOB). Overall, this study suggests that aeration requirements for post-aerobic digestion should be based on NO2 - shunt and not complete simultaneous nitrification denitrification. PRACTITIONER POINTS: AOB are a key feature of PAD microbial communities NOB are present, but in much lower abundance than AOB High nitrite accumulation ratio suggests shortcut nitrite as the main mechanism for nitrogen removal Nitritation in PAD reactors is sustained at temperatures as high as 40°C No ammonia oxidation occurred at 50°C implying different mechanisms of nitrogen removal including ammonia stripping.
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Affiliation(s)
| | - Patrick McNamara
- Black & Veatch, Overland Park, Kansas, USA
- Department of Civil, Construction and Environmental Engineering, Marquette University, Milwaukee, Wisconsin, USA
| | | | | | - Mike Young
- Trinity River Authority of Texas, Arlington, Texas, USA
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7
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Pang Y, Wang J. Various electron donors for biological nitrate removal: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 794:148699. [PMID: 34214813 DOI: 10.1016/j.scitotenv.2021.148699] [Citation(s) in RCA: 124] [Impact Index Per Article: 41.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 06/22/2021] [Accepted: 06/22/2021] [Indexed: 06/13/2023]
Abstract
Nitrate (NO3-) pollution in water and wastewater has become a serious global issue. Biological denitrification, which reduces NO3- to N2 (nitrogen gas) by denitrifying microorganisms, is an efficient and economical process for the removal of NO3- from water and wastewater. During the denitrification process, electron donor is required to provide electrons for reduction of NO3-. A variety of electron donors, including organic and inorganic compounds, can be used for denitrification. This paper reviews the state of the art of various electron donors used for biological denitrification. Depending on the types of electron donors, denitrification can be classified into heterotrophic and autotrophic denitrification. Heterotrophic denitrification utilizes organic compounds as electron donors, including low-molecular-weight organics (e.g. acetate, methanol, glucose, benzene, methane, etc.) and high-molecular-weight organics (e.g. cellulose, polylactic acid, polycaprolactone, etc.); while autotrophic denitrification utilizes inorganic compounds as electron donors, including hydrogen (H2), reduced sulfur compounds (e.g. sulfide, element sulfur and thiosulfate), ferrous iron (Fe2+), iron sulfides (e.g. FeS, Fe1-xS and FeS2), arsenite (As(Ш)) and manganese (Mn(II)). The biological denitrification processes and the representative denitrifying microorganisms are summarized based on different electron donors, and their denitrification performance, operating costs and environmental impacts are compared and discussed. The pilot- or full-scale applications were summarized. The concluding remarks and future prospects were provided. The biodegradable polymers mediated heterotrophic denitrification, as well as H2 and sulfur mediated autotrophic denitrification are promising denitrification processes for NO3- removal from various types of water and wastewater.
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Affiliation(s)
- Yunmeng Pang
- Laboratory of Environmental Technology, INET, Tsinghua University, Beijing 100084, PR China
| | - Jianlong Wang
- Laboratory of Environmental Technology, INET, Tsinghua University, Beijing 100084, PR China; Beijing Key Laboratory of Radioactive Waste Treatment, INET, Tsinghua University, Beijing 100084, PR China.
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8
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Chen X, Huo P, Liu J, Li F, Yang L, Li X, Wei W, Liu Y, Ni BJ. Model predicted N 2O production from membrane-aerated biofilm reactor is greatly affected by biofilm property settings. CHEMOSPHERE 2021; 281:130861. [PMID: 34020186 DOI: 10.1016/j.chemosphere.2021.130861] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 04/23/2021] [Accepted: 05/08/2021] [Indexed: 06/12/2023]
Abstract
Even though modeling has been frequently used to understand the autotrophic deammonification-based membrane-aerated biofilm reactor (MABR), the relationships between system-specific biofilm property settings and model predicted N2O production have yet to be clarified. To this end, this study investigated the impacts of 4 key biofilm property settings (i.e., biofilm thickness/compactness, boundary layer thickness, diffusivity of soluble components in the biofilm structure, and biofilm discretization) on one-dimensional modeling of the MABR, with the focus on its N2O production. The results showed that biofilm thickness/compactness (200-1000 μm), diffusivity of soluble components in the biofilm structure (reduction factor of diffusivity: 0.2-0.9), and biofilm discretization (12-28 grid points) significantly influenced the simulated N2O production, while boundary layer thickness (0-300 μm) only played a marginal role. In the studied ranges of biofilm property settings, distinct upper and lower bounds of N2O production factor (i.e., the percentage ratio of N2O formed to NH4+ removed, 5.5% versus 2.3%) could be predicted. In addition to the microbial community structure, the N2O production pathway contribution differentiation was also subject to changes in biofilm property settings. Therefore, biofilm properties need to be quantified experimentally or set properly to model N2O production from the MABR correctly. As a good practice for one-dimensional modeling of N2O production from biofilm-based reactors, especially the MABR performing autotrophic deammonification, the essential information about those influential biofilm property settings identified in this study should be disclosed and clearly documented, thus ensuring both the reproducibility of modeling results and the reliable applications of N2O models.
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Affiliation(s)
- Xueming Chen
- Fujian Provincial Engineering Research Center of Rural Waste Recycling Technology, College of Environment and Resources, Fuzhou University, Fujian, 350116, China.
| | - Pengfei Huo
- Fujian Provincial Engineering Research Center of Rural Waste Recycling Technology, College of Environment and Resources, Fuzhou University, Fujian, 350116, China
| | - Jinzhong Liu
- Fujian Provincial Engineering Research Center of Rural Waste Recycling Technology, College of Environment and Resources, Fuzhou University, Fujian, 350116, China
| | - Fuyi Li
- Fujian Provincial Engineering Research Center of Rural Waste Recycling Technology, College of Environment and Resources, Fuzhou University, Fujian, 350116, China
| | - Linyan Yang
- School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, 200237, China
| | - Xianhui Li
- Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, Institute of Environmental and Ecological Engineering, Guangdong University of Technology, Guangzhou, 510006, China
| | - Wei Wei
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW, 2007, Australia
| | - Yiwen Liu
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW, 2007, Australia
| | - Bing-Jie Ni
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW, 2007, Australia.
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Zak N, Marks R, Perez-Calleja P, Nerenberg R, Doudrick K. A computational model for the catalytic hydrogel membrane reactor. WATER RESEARCH 2020; 185:116199. [PMID: 32726717 DOI: 10.1016/j.watres.2020.116199] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 07/16/2020] [Accepted: 07/17/2020] [Indexed: 06/11/2023]
Abstract
The catalytic hydrogel membrane reactor (CHMR) is a promising new technology for hydrogenation of aqueous contaminants in drinking water. It offers numerous benefits over conventional three-phase reactors, including immobilization of nano-catalysts, high reactivity, and control over the hydrogen (H2) supply concentration. In this study, a computational model of the CHMR was developed using AQUASIM and calibrated with 32 experimental datasets for a nitrite (NO2-)-reducing CHMR using palladium (Pd) nano-catalysts (~4.6 nm). The model was then used to identify key factors impacting the behavior of the CHMR, including hydrogel catalyst density, H2 supply pressure, influent and bulk NO2- concentrations, and hydrogel thickness. Based on the model calibration, the reaction rate constants for the NO2- steady-state adsorption Hinshelwood reaction equation, k1 and k2, were 0.0039 m3 mole-Pd-1 s-1 and 0.027 (mole-H2 m3)1/2 mole-Pd-1 s-1, respectively. The reactant flux, which is the overall NO2- removal rate for the CHMR, is affected by the NO2- reduction rate at each catalyst site, which is in turn controlled by the available NO2- and H2 concentrations that are regulated by their mass transport behavior. Reactant transport in the CHMR is counter-diffusional. So for thick hydrogels, the concurrent concentrations of NO2- and H2 are limiting in the middle region along the x-y plane of the hydrogel, which results in a low overall NO2- removal rate (i.e., flux). Thinner hydrogels provide higher concurrent reactant concentrations throughout the hydrogel, resulting in higher fluxes. However, if the hydrogel is too thin, the flux becomes limited by the amount of Pd that can be loaded, and unused H2 can diffuse into the bulk and promote biofilm growth. The hydrogel thickness that maximized the NO2- flux ranged between 30 and 150 μm for the conditions tested. The computational model is the first to describe CHMR behavior, and it is an important tool for the further development of the CHMR. It also can be adapted to assess CHMR behavior for other contaminants or catalysts or used for other types of interfacial catalytic membrane reactors.
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Affiliation(s)
- Nicholas Zak
- University of Notre Dame, Department of Civil and Environmental Engineering and Earth Sciences, 156 Fitzpatrick Hall, 46556 Notre Dame, IN, USA
| | - Randal Marks
- University of Notre Dame, Department of Civil and Environmental Engineering and Earth Sciences, 156 Fitzpatrick Hall, 46556 Notre Dame, IN, USA
| | - Patricia Perez-Calleja
- University of Notre Dame, Department of Civil and Environmental Engineering and Earth Sciences, 156 Fitzpatrick Hall, 46556 Notre Dame, IN, USA
| | - Robert Nerenberg
- University of Notre Dame, Department of Civil and Environmental Engineering and Earth Sciences, 156 Fitzpatrick Hall, 46556 Notre Dame, IN, USA
| | - Kyle Doudrick
- University of Notre Dame, Department of Civil and Environmental Engineering and Earth Sciences, 156 Fitzpatrick Hall, 46556 Notre Dame, IN, USA.
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10
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Chen X, Yang L, Sun J, Wei W, Liu Y, Ni BJ. Influences of Longitudinal Heterogeneity on Nitrous Oxide Production from Membrane-Aerated Biofilm Reactor: A Modeling Perspective. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:10964-10973. [PMID: 32786580 DOI: 10.1021/acs.est.0c04067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
As a promising technology for sustainable nitrogen removal from wastewater, the membrane-aerated biofilm reactors (MABRs) performing autotrophic deammonification are faced with the problem of unwanted production of nitrous oxide (N2O, a potent greenhouse gas). As a common tool to study N2O production from such an MABR, the traditional one-dimensional modeling approach fails to simulate the existence of longitudinal gradients in the reactor and therefore might render N2O production significantly deviated from reality. To this end, this work aims to study the influences of key longitudinal gradients (i.e., in oxygen, liquid-phase components, and biofilm thickness) on the N2O production from a typical MABR performing autotrophic deammonification by applying a modified version of a newly developed compartmental model. Through comparing the modeling results of different reactor configurations, this work reveals that the single impact of the longitudinal gradients studied on the N2O production from the MABR follows the order: oxygen (significant) > liquid-phase components (slight) > biofilm thickness (almost none). When multiple longitudinal gradients are present, they become correlated and would jointly influence the N2O production and nitrogen removal of the MABR. The results also show the need for multispot measurements to get an accurate representation of spatial biofilm features of the MABR configuration with the membrane lumen designed/operated as a plug flow reactor. While the traditional modeling approach is acceptable to evaluate the nitrogen removal in most cases, it might overestimate or underestimate the N2O production from the MABR with at least one of the longitudinal gradients in oxygen and liquid-phase components. For such an MABR, the longitudinal heterogeneity in biofilm thickness and the number of biofilm thickness classes to be included in the model would also make a difference to the simulation results, especially the N2O production. The work also proposes that under the studied conditions, proper design/operation of the MABR in consideration of longitudinal heterogeneity has the theoretical potential of reducing the N2O production by 77% without significantly compromising the nitrogen removal.
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Affiliation(s)
- Xueming Chen
- College of Environment and Resources, Fuzhou University, Fujian 350116, China
| | - Linyan Yang
- School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Jing Sun
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Wei Wei
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW 2007, Australia
| | - Yiwen Liu
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW 2007, Australia
| | - Bing-Jie Ni
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW 2007, Australia
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11
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Yang Q, Cui B, Zhou Y, Li J, Liu Z, Liu X. Impact of gas-water ratios on N 2O emissions in biological aerated filters and analysis of N 2O emissions pathways. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 723:137984. [PMID: 32213406 DOI: 10.1016/j.scitotenv.2020.137984] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 03/12/2020] [Accepted: 03/15/2020] [Indexed: 06/10/2023]
Abstract
Biological aerated filter (BAF) is a widely applied biofilm process for wastewater treatment. However, characteristics of nitrous oxide (N2O) production in BAF are rarely reported. In this study, two tandem BAFs treating domestic wastewater were built up, and different gas-water ratios were controlled to explore N2O production pathway. Results showed that N2O production increased with increasing gas-water ratio in both BAFs; higher gas-water ratio promoted more N2O releasing from hydroxylamine oxidation process. To improve nitrogen removal performance and reduce N2O emission, the optimal gas-water ratios for BAF1 and BAF2 were 5:1 and 1.5:1, respectively. Most of N2O was produced from ammonia oxidizing bacteria (AOB) denitrification and hydroxylamine oxidation in BAF1, and heterotrophic denitrification contributed to relieve N2O emission. In BAF2, N2O was emitted from AOB denitrification and hydroxylamine oxidation by 87.8% and 12.2%, respectively. Heterotrophic denitrification is a N2O sink in BAF, causing BAF1 produced less N2O than BAF2 with the same gas-water ratio. Enhancing heterotrophic denitrification and anaerobic ammonium oxidation (Anammox) activity could reduce the release of N2O in BAFs.
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Affiliation(s)
- Qing Yang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing 100124, PR China.
| | - Bin Cui
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing 100124, PR China
| | - Yao Zhou
- Beijing Drainage Group Water Design & Research Institute Co., Ltd, Beijing 100022, PR China
| | - Jianmin Li
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing 100124, PR China
| | - Zhibin Liu
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing 100124, PR China
| | - Xiuhong Liu
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing 100124, PR China
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12
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Mielcarek A, Rodziewicz J, Janczukowicz W, Struk-Sokołowska J. The impact of biodegradable carbon sources on nutrients removal in post-denitrification biofilm reactors. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 720:137377. [PMID: 32143032 DOI: 10.1016/j.scitotenv.2020.137377] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Revised: 01/28/2020] [Accepted: 02/15/2020] [Indexed: 06/10/2023]
Abstract
Wastewater from households wastewater treatment plants (HWWTP) is discharged to the ground or to the surface waters. Special consideration should be given to the improvement of HWWTP effectiveness, particularly in relation to nutrients. The addition of biodegradable carbon sources to biofilm reactor, can enhance microbial activity but may also lead to filling clogging. The study aimed to compare 3 different organic substrates: acetic acid (commonly applied)and two untypical - citric acid and waste beer, under the same operational conditions in a post-denitrification biofilm reactor. The study investigated the impact of a type of organic substrate, low pH and time on: (1) biofilm growth, (2) the characteristics of extracellular polymeric substances (EPS), (3) the kinetics of nutrients removal and (4) reactor clogging. Results were referred to (5) the effectiveness of nutrients removal. The study demonstrated that low pH assured the development of a thinbiofilm. Citric acid ensured the lowest biomass volume, being by 53% lower than in the reactor with acetic acid and by as much as 61% lower than in the reactor with waste beer. The soluble EPS fraction prevailed in the total EPS in all reactors. The content of the tightly bound EPS fraction ranged from 26.93% (citric acid) to 36.32% (waste beer). Investigations showed also a high ratio of exoproteins to polysaccharide in all fractions, which indicated a significant role of proteins in developing a highly-proliferating biofilm. The treated wastewater met requirements of Polish regulations concerning COD and nitrogen concentrations.
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Affiliation(s)
- Artur Mielcarek
- University of Warmia and Mazury in Olsztyn, Department of Environment Engineering, Warszawska St. 117a, Olsztyn 10-719, Poland.
| | - Joanna Rodziewicz
- University of Warmia and Mazury in Olsztyn, Department of Environment Engineering, Warszawska St. 117a, Olsztyn 10-719, Poland.
| | - Wojciech Janczukowicz
- University of Warmia and Mazury in Olsztyn, Department of Environment Engineering, Warszawska St. 117a, Olsztyn 10-719, Poland.
| | - Joanna Struk-Sokołowska
- Bialystok University of Technology, Department of Environmental Engineering Technology, Wiejska St. 45E, Bialystok 15-351, Poland.
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Li Y, Zhao R, Wang L, Niu L, Wang C, Hu J, Wu H, Zhang W, Wang P. Silver nanoparticles and Fe(III) co-regulate microbial community and N 2O emission in river sediments. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 706:135712. [PMID: 31785899 DOI: 10.1016/j.scitotenv.2019.135712] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 10/20/2019] [Accepted: 11/21/2019] [Indexed: 06/10/2023]
Abstract
The effects of environmental concentration silver nanoparticles (ecAgNPs) on microbial communities and the nitrogen cycling in river sediments remain largely uncharacterized. As a fundamental component of sediments, Fe(III) can interact with AgNPs and participate in nitrogen transformation processes. N2O is an important intermediate in nitrogen transformation processes and can be a potent greenhouse gas with significant environmental effects. However, the impacts of the co-existence of AgNPs and Fe(III) on microbial communities and N2O emission in river sediments are still unclear. In the present study, mesocosm experiments were conducted to assess the changes of microbial communities and N2O emission in response to the co-existence of AgNPs and environmental concentration Fe(III). Our results revealed that the microbial community diversity and N2O emission in river sediments responded differently to ecAgNPs (0.05 mg/kg) and high-polluting concentration AgNPs (hcAgNPs, 5 mg/kg), which was further regulated by the environmental concentration Fe(III) (1 mg/g and 10 mg/g). After ecAgNPs treatments, a marked increase was observed in microbial diversity compared to hcAgNPs treatments, regardless of the Fe(III) concentration in the sediment. The β-NTI index indicated that AgNPs had stronger impacts on phylogenetic distance of bacterial communities in sediments containing 1 mg/g Fe(III) than that containing 10 mg/g Fe(III). In sediments containing 1 mg/g Fe(III), ecAgNPs did not affect N2O emission, but hcAgNPs significantly inhibited the emission of N2O. However, in sediments containing 10 mg/g Fe(III), N2O emission was significantly stimulated upon exposure to ecAgNPs, but the inhibition effect of hcAgNPs was barely observed. Functional prediction and real-time PCR analyses indicated that AgNPs and Fe(III) predominantly affected N2O emissions by affecting the abundance of the nirK gene. Our results provide new insights into the ecological impacts of the co-existence of environmental concentration AgNPs and Fe(III) in altering microbial communities and nitrogen transformation functions in river sediments.
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Affiliation(s)
- Yi Li
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, PR China
| | - Ruiqi Zhao
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, PR China
| | - Longfei Wang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, PR China
| | - Lihua Niu
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, PR China.
| | - Chao Wang
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, PR China.
| | - Jiaxin Hu
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, PR China
| | - Hainan Wu
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, PR China
| | - Wenlong Zhang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, PR China
| | - Peifang Wang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, PR China
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14
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Iannacone F, Di Capua F, Granata F, Gargano R, Pirozzi F, Esposito G. Effect of carbon-to-nitrogen ratio on simultaneous nitrification denitrification and phosphorus removal in a microaerobic moving bed biofilm reactor. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2019; 250:109518. [PMID: 31518800 DOI: 10.1016/j.jenvman.2019.109518] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 08/16/2019] [Accepted: 09/02/2019] [Indexed: 06/10/2023]
Abstract
In this study, long-term simultaneous nitrification denitrification (SND) and phosphorous removal were investigated in a continuous-flow microaerobic MBBR (mMBBR) operated at a dissolved oxygen (DO) concentration of 1.0 (±0.2) mg L-1. The mMBBR performance was evaluated at different feed carbon-to-nitrogen (C/N) ratios (2.7, 4.2 and 5.6) and HRTs (2 days and 1 day). Stable long-term mMBBR operation and chemical oxygen demand (COD), total inorganic nitrogen (TIN) and phosphorous (P-PO43-) removal efficiencies up to 100%, 68% and 72%, respectively, were observed at a feed C/N ratio of 4.2. Lower TIN removal efficiency and unstable performance were observed at feed C/N ratios of 2.7 and 5.6, respectively. HRT decrease from 2 days to 1 day resulted in transient NH4+ accumulation and higher NO2-/NO3- ratio in the effluent. Batch activity tests showed that biofilm cultivation at a feed C/N ratio of 4.2 resulted in the highest denitrifying activity (189 mg N gVSS-1 d-1), whereas the highest nitrifying activity (316 mg N gVSS-1 d-1) was observed after cultivation at a feed C/N ratio of 2.7. Thermodynamic modeling with Visual MINTEQ and stoichiometric evaluations revealed that P removal was mainly biological and can be attributed to the P-accumulating capacity of denitrifying bacteria.
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Affiliation(s)
- Francesca Iannacone
- Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, via Gaetano di Biasio 43, 03043, Cassino, Italy
| | - Francesco Di Capua
- Department of Civil, Architectural and Environmental Engineering, University of Naples Federico II, via Claudio 21, 80125, Naples, Italy.
| | - Francesco Granata
- Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, via Gaetano di Biasio 43, 03043, Cassino, Italy
| | - Rudy Gargano
- Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, via Gaetano di Biasio 43, 03043, Cassino, Italy
| | - Francesco Pirozzi
- Department of Civil, Architectural and Environmental Engineering, University of Naples Federico II, via Claudio 21, 80125, Naples, Italy
| | - Giovanni Esposito
- Department of Civil, Architectural and Environmental Engineering, University of Naples Federico II, via Claudio 21, 80125, Naples, Italy
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15
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Chen X, Sin G, Ni BJ. Impact of granule size distribution on nitrous oxide production in autotrophic nitrogen removal granular reactor. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 689:700-708. [PMID: 31280151 DOI: 10.1016/j.scitotenv.2019.06.490] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 06/23/2019] [Accepted: 06/28/2019] [Indexed: 06/09/2023]
Abstract
This work applied an approach with reactor compartmentation and artificial diffusion to study the impact of granule size distribution on the autotrophic granular reactor performing partial nitritation and anaerobic ammonium oxidation with focus on the nitrous oxide (N2O) production. The results show that the microbial community and the associated N2O production rates in the granular structure are significantly influenced by the granule size distribution. Heterotrophic bacteria growing on microbial decay products tend to be retained and contribute to N2O consumption in relatively small granules. Ammonium-oxidizing bacteria are mainly responsible for N2O production via two pathways in granules of different sizes. Under the conditions studied, such heterogeneity in the granular structure disappears when the number of granule size classes considered reaches >4, where heterotrophic bacteria are completely outcompeted in the granules. In general, larger granules account for a higher portion of the net N2O production, while the trend regarding the volumetric contribution of each granule size class changes with a varied number of granule size classes, due to the different contributions of relevant N2O production pathways (with the heterotrophic denitrification pathway being the most decisive). Overall, with the increasing extent of granule size distribution, the nitrogen removal efficiency decreases slightly but consistently, whereas the N2O production factor increases until the number of granule size classes reaches 4 or above. Practical implications of this work include: i) granules should be controlled as well-distributed as possible in order to obtain high nitrogen removal while minimizing N2O production; ii) granule size distribution should be considered carefully and specifically when modelling N2O production/emission from the autotrophic nitrogen removal granular reactor.
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Affiliation(s)
- Xueming Chen
- Process and Systems Engineering Center (PROSYS), Department of Chemical and Biochemical Engineering, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - Gürkan Sin
- Process and Systems Engineering Center (PROSYS), Department of Chemical and Biochemical Engineering, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
| | - Bing-Jie Ni
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW 2007, Australia.
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16
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Cecconet D, Bolognesi S, Callegari A, Capodaglio AG. Simulation tests of in situ groundwater denitrification with aquifer-buried biocathodes. Heliyon 2019; 5:e02117. [PMID: 31388574 PMCID: PMC6667668 DOI: 10.1016/j.heliyon.2019.e02117] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 07/09/2019] [Accepted: 07/17/2019] [Indexed: 01/28/2023] Open
Abstract
Bioelectrochemical systems (BES) application was proposed for a variety of specific uses, due to these systems’ characteristics: electrodes can act as virtually inexhaustible electron acceptors/donors, offering a growth-support surface for microorganisms, and stimulating naturally-occurring microbial degradation activities. In situ, groundwater denitrification therefore seems to be a potential candidate for their use. In this study, buried biocathodes were operated in laboratory settings for the simulation of in situ groundwater denitrification. Two alternative configurations were tested: biocathode buried in sand, and biocathode buried in gravel. A control test with a biocathode in absence of sand/gravel was also performed. In all the cases, biocathodes were driven by power supply or potentiostat to guarantee a steady electron flux to the cathode. The presence of sand and gravel strongly influenced the denitrification process: in both configurations, accumulation of intermediate N-forms was detected, suggesting that the denitrification process was only partially achieved. In addition, a significant decrease (in the 20–36% range) in nitrate removal rates was measured in sand and gravel setups compared to the control reactor; this issue could be attributed to lack of recirculation that limited contact between substrate and electrode-adherent biofilm. Biocathodes buried in gravel obtained better results than those buried in sand due to the lower packing of the medium. The results of this study suggest that, in order to achieve successful in situ treatment, special design of submerged-biocathodic BESs is necessary.
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Affiliation(s)
- Daniele Cecconet
- Department of Civil Engineering and Architecture, University of Pavia, Via Adolfo Ferrata 3, 27100, Pavia, Italy
| | - Silvia Bolognesi
- Department of Civil Engineering and Architecture, University of Pavia, Via Adolfo Ferrata 3, 27100, Pavia, Italy.,LEQUIA, Institute of the Environment, University of Girona, Campus Montilivi, Carrer Maria Aurèlia Capmany, 69, E-17003, Girona, Catalonia, Spain
| | - Arianna Callegari
- Department of Civil Engineering and Architecture, University of Pavia, Via Adolfo Ferrata 3, 27100, Pavia, Italy
| | - Andrea G Capodaglio
- Department of Civil Engineering and Architecture, University of Pavia, Via Adolfo Ferrata 3, 27100, Pavia, Italy
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17
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Evaluation of the Nitrous Oxide Emission Reduction Potential of an Aerobic Bioreactor Packed with Carbon Fibres for Swine Wastewater Treatment. ENERGIES 2019. [DOI: 10.3390/en12061013] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Nitrous oxide (N2O) is a potent greenhouse gas that is emitted from wastewater treatment plants. To reduce emissions of N2O from swine wastewater treatment plants, we constructed an experimental aerobic bioreactor packed with carbon fibres (ca. 1 m3 bioreactor) as an alternative to conventional activated sludge treatment. The N2O emission factor for the aerobic bioreactor packed with carbon fibres (CF) was 0.002 g N2O-N/g TN-load and the value for the typical activated sludge (AS) reactor was 0.013 g N2O-N/g TN-load. The CF treatment method achieved more than 80% reduction of N2O emissions, compared with the AS treatment method. The experimental introduction of a CF carrier into an actual wastewater treatment plant also resulted in a large reduction in N2O generation. Specifically, the N2O emission factors decreased from 0.040 to 0.005 g N2O-N/g TN-load following application of the carrier. This shows that it is possible to reduce N2O generation by more than 80% by using a CF carrier during the operation of an actual wastewater treatment plant. Some bacteria from the phylum Chloroflexi, which are capable of reducing N2O emissions, were detected at a higher frequency in the biofilm on the CF carrier than in the biofilm formed on the AS reactor.
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18
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Chen X, Ni B, Sin G. Nitrous oxide production in autotrophic nitrogen removal granular sludge: A modeling study. Biotechnol Bioeng 2019; 116:1280-1291. [DOI: 10.1002/bit.26937] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 01/19/2019] [Accepted: 01/24/2019] [Indexed: 11/09/2022]
Affiliation(s)
- Xueming Chen
- Process and Systems Engineering Center (PROSYS), Department of Chemical and Biochemical Engineering Technical University of Denmark Lyngby Denmark
| | - Bing‐Jie Ni
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney Sydney New South Wales Australia
| | - Gürkan Sin
- Process and Systems Engineering Center (PROSYS), Department of Chemical and Biochemical Engineering Technical University of Denmark Lyngby Denmark
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19
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Pan Y, Liu Y, Peng L, Ngo HH, Guo W, Wei W, Wang D, Ni BJ. Substrate Diffusion within Biofilms Significantly Influencing the Electron Competition during Denitrification. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:261-269. [PMID: 30511837 DOI: 10.1021/acs.est.8b05476] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A common and long-existing operational issue of wastewater denitrification is the unexpected accumulation of nitrite (NO2-) that could suppress the activity of various microorganisms involved in biological wastewater treatment process and nitrous oxide (N2O) that could emit as a potent greenhouse gas. Recently, it has been confirmed that the accumulation of these denitrification intermediates in biological wastewater treatment process is greatly influenced by the electron competition between the four denitrification steps. However, little is known about this in biofilm systems. In this work, we applied a mathematical model that links carbon oxidation and nitrogen reduction processes through a pool of electron carriers, to assess electron competition in denitrifying biofilms. Simulations were performed comprehensively at seven combinations of electron acceptor addition scheme (i.e., simultaneous addition of one, two or three among nitrate (NO3-), NO2-, and N2O) to compare the effect of electron competition on NO3-, NO2- and N2O reduction. Overall, the effects of substrate loading, biofilm thickness and effective diffusion coefficients on electron competition are not always intuitive. Model simulations show that electron competition was intensified due to the substrate load limitation (from 120 to 20 mg COD/L) and increasing biofilm thicknesses (from 0.1 to 1.6 mm) in most cases, where electrons were prioritized to nitrite reductase because of the insufficient electron donor availability in the biofilm. In contrast, increasing effective diffusion coefficients did not pose a significant effect on electron competition and only increased electrons distributed to nitrite reductase when both NO2- and N2O are added.
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Affiliation(s)
- Yuting Pan
- Department of Environmental Science and Engineering, College of Architecture and Environment , Sichuan University , Chengdu , Sichuan 610065 , China
| | - Yiwen Liu
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering , University of Technology Sydney , Sydney , New South Wales 2007 , Australia
| | - Lai Peng
- School of Resources and Environmental Engineering , Wuhan University of Technology , Luoshi Road 122 , Wuhan , Hubei 430070 , China
| | - Huu Hao Ngo
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering , University of Technology Sydney , Sydney , New South Wales 2007 , Australia
| | - Wenshan Guo
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering , University of Technology Sydney , Sydney , New South Wales 2007 , Australia
| | - Wei Wei
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering , University of Technology Sydney , Sydney , New South Wales 2007 , Australia
| | - Dongbo Wang
- Key Laboratory of Environmental Biology and Pollution Control, College of Environmental Science and Engineering , Hunan University , Changsha , 410082 , China
| | - Bing-Jie Ni
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering , University of Technology Sydney , Sydney , New South Wales 2007 , Australia
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20
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Sabba F, Terada A, Wells G, Smets BF, Nerenberg R. Nitrous oxide emissions from biofilm processes for wastewater treatment. Appl Microbiol Biotechnol 2018; 102:9815-9829. [DOI: 10.1007/s00253-018-9332-7] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 08/13/2018] [Accepted: 08/15/2018] [Indexed: 01/21/2023]
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21
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Jia W, Chen Y, Zhang J, Li C, Wang Q, Li G, Yang W. Response of greenhouse gas emissions and microbial community dynamics to temperature variation during partial nitrification. BIORESOURCE TECHNOLOGY 2018; 261:19-27. [PMID: 29653330 DOI: 10.1016/j.biortech.2018.03.137] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 03/29/2018] [Accepted: 03/30/2018] [Indexed: 06/08/2023]
Abstract
This study investigated the greenhouse gas emission characteristics and microbial community dynamics with the variation of temperature during partial nitrification. Low temperature weakened nitrite accumulation, and partial nitrification would shift to complete nitrification easily at 15 °C. Based on CO2 equivalents (CO2-eq), partial nitrification process released 2.7 g of greenhouse gases per gMLSS per cycle, and N2O accounted for more than 98% of the total CO2-eq emission. The total CO2-eq emission amount at 35 °C was 45.6% and 153.4% higher than that at 25 °C and 15 °C, respectively. During partial nitrification, the microbial community diversity greatly declined compared with seed sludge. However, the diversity was enhanced at low temperature. The abundance of Betaproteobacteria at class level increased greatly during partial nitrification. Proteobacteria abundance declined while Nitrospira raised at low temperature. The nosZ community abundance was not affected by temperature, although N2O emission was varied with the operating temperature.
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Affiliation(s)
- Wenlin Jia
- School of Chemistry and Materials Science, Jiangsu Normal University, Xuzhou 221116, China
| | - Yunfan Chen
- School of Chemistry and Materials Science, Jiangsu Normal University, Xuzhou 221116, China
| | - Jian Zhang
- Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100, China
| | - Cong Li
- School of Environment and Planning, Liaocheng University, Liaocheng 252000, China
| | - Qian Wang
- School of Chemistry and Materials Science, Jiangsu Normal University, Xuzhou 221116, China
| | - Guangchao Li
- School of Chemistry and Materials Science, Jiangsu Normal University, Xuzhou 221116, China
| | - Weihua Yang
- School of Chemistry and Materials Science, Jiangsu Normal University, Xuzhou 221116, China.
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22
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Immobilization of Azospira sp. strain I13 by gel entrapment for mitigation of N2O from biological wastewater treatment plants: Biokinetic characterization and modeling. J Biosci Bioeng 2018; 126:213-219. [DOI: 10.1016/j.jbiosc.2018.02.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 02/13/2018] [Accepted: 02/18/2018] [Indexed: 11/23/2022]
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23
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Liu Y, Ngo HH, Guo W, Peng L, Chen X, Wang D, Pan Y, Ni B. Modeling electron competition among nitrogen oxides reduction and N
2
O accumulation in hydrogenotrophic denitrification. Biotechnol Bioeng 2018; 115:978-988. [DOI: 10.1002/bit.26512] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 11/20/2017] [Accepted: 12/04/2017] [Indexed: 11/09/2022]
Affiliation(s)
- Yiwen Liu
- Centre for Technology in Water and WastewaterSchool of Civil Environmental EngineeringUniversity of Technology SydneySydneyNew South WalesAustralia
- Water Chemistry and Water TechnologyEngler‐Bunte‐InstitutKarlsruhe Institute of TechnologyKarlsruheGermany
| | - Huu H. Ngo
- Centre for Technology in Water and WastewaterSchool of Civil Environmental EngineeringUniversity of Technology SydneySydneyNew South WalesAustralia
| | - Wenshan Guo
- Centre for Technology in Water and WastewaterSchool of Civil Environmental EngineeringUniversity of Technology SydneySydneyNew South WalesAustralia
| | - Lai Peng
- Department of Bioscience EngineeringResearch Group of Sustainable EnergyAir and Water TechnologyUniversity of AntwerpAntwerpBelgium
| | - Xueming Chen
- Department of Chemical and Biochemical EngineeringProcess and Systems Engineering Center (PROSYS)Technical University of DenmarkDenmark
| | - Dongbo Wang
- College of Environmental Science and EngineeringHunan UniversityChangshaP.R. China
- Key Laboratory of Environmental Biology and Pollution Control (Hunan University)Ministry of EducationChangshaP.R. China
| | - Yuting Pan
- Department of Environmental Science and EngineeringSchool of Architecture and EnvironmentSichuan UniversityChengduSichuanP.R. China
| | - Bing‐Jie Ni
- State Key Laboratory of Pollution Control and Resources ReuseCollege of Environmental Science and EngineeringTongji UniversityShanghaiP.R. China
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